If Mind Is a True Believer, Placebo Effect Can Work Wonders
Deep within the human mind lies a little-known power of extraordinary force. The wise men of ancient civilizations used the power to achieve remarkable feats. And now you, too, can tap into this amazing ability.
If that sounds like a pitch for New Age mumbo-jumbo about holistic crystals or some such, don’t be put off. It is a pitch for something at least as amazing, and, all the better, a pitch for something quite probably real.
It’s called the placebo effect, and you can also think of it as faith healing or as “the power of suggestion” or even as witch-doctoring. Although often pseudoscientific or sometimes fraudulent, all of these succeed in certain ways because of a phenomenon that biomedical scientists now know to be powerful and useful. Maybe it should be called the placebo force.
The word placebo is Latin for “I shall please.” It was adopted long before the era of scientific medicine by physicians who knew they had little to offer patients except hope and the sense that something was being done for them, even if it was only the laying on of hands or the administration of an impressively prepared potion. But scientists now know that there really is a placebo force--a power, or probably several powers, in the brain that can heal the body of many different (though definitely not all) ailments--from warts and battle wounds to infections and headaches. The power must, however, be invoked in the right way.
It doesn’t matter what form the placebo takes. It can be a country doctor’s sugar pill or a Navajo medicine man’s five days of chanting and sand-painting inside the sacred hogan. It can be a thwak upside the head from a tent revivalist faith healer (even one of the variety shown to be outright frauds) or it can be a mother’s kiss. The one paramount factor that matters, scientific experiments show, is that the patient truly believes the method can work. “Faith healing” turns out to be an apt name, though the religious kind of faith is not necessary. Faith in the method is.
If that faith is present, messages go out from the believing brain to communicate with many different physiological mechanisms throughout the body. Researchers believe the messages start out as ordinary nerve impulses transmitted from the brain through the nervous system to the afflicted part of the body. There the nerves release certain chemicals that act on the cells to correct the problem.
The placebo effect is not a cure-all. But most diseases are self-limiting, and the normal disease-fighting and recuperative powers of the body eventually triumph. The placebo effect merely seems to speed up these normal processes--healing wounds faster and boosting the immune system’s attack on infection.
Perhaps the most studied placebo mechanism is the one that helps control pain. One of the most dramatic examples arose in the 1950s, when a curious form of surgery was being touted as a cure for the severe chest pains of angina. Heart surgeons would open a patient’s chest and tie off the internal mammary artery. This was supposed to divert more blood to the heart’s coronary arteries and relieve the pain.
Early reports on the procedure, called an internal mammary artery ligation, were stunning. More than 90% of patients reported dramatic relief of pain, and 75% performed better on stress tests. But many doctors were suspicious. They devised an experiment the likes of which would not be allowed under today’s rules on human experimentation.
Angina patients were randomly assigned to either of two groups. One group received the standard artery ligation. The other got a placebo operation, but the patients were not told. They got the usual elaborate preparations for surgery and were anesthetized. Surgeons cut open each chest, looked at the artery and sewed up the incision. When the patients came to, they had the expected postoperative pain, a sure sign that something powerful had been done to them, and stitches in the right place.
Those who got the sham surgery reported just as much pain relief as those who got the real thing. Even though some 10,000 of the operations had been done, the experiment proved they were doing no good--at least not directly. It proved that what was doing good was the placebo effect. The patients believed that all the most advanced techniques of modern medicine were being applied to them, and the placebo force did the rest.
Internal mammary artery ligations were stopped immediately, but the question remains: How did the placebo force cure the angina?
The answer has become clear in just the last few years. When the brain wants to kill pain, it sends signals to the painful area that cause the local nerve cells to release a natural pain-killing substance called endorphin. This is the morphinelike molecule that also produces the “runner’s high.”
Jon Levine, a pharmacologist at the UC San Francisco, has even found that a placebo pill has the pain-killing power of 8 milligrams of morphine or 80 milligrams of Demerol. He determined this by giving volunteers the drug naloxone, which is known to block the action of morphine, before treating their pain with placebos--with no effect.
The fact that naloxone blocks the placebo effect is good evidence that the effect is the result of the morphinelike substance endorphin. Levine found that the amount of naloxone needed to do this was the amount needed to block 8 milligrams of morphine. A typical morphine pill is 10 milligrams. Pain is not the only thing placebos can treat.
In 1955, Henry Beecher of the Harvard Medical School reviewed published studies of the placebo effect and found the phenomenon was good for treating postsurgical wound pain, seasickness, headaches, coughs, anxiety and other nervous disorders. Since then, the medical literature has exploded with still wider evidence of the placebo effect’s range. Placebos have produced improvement in high blood pressure, depression, acne, asthma, colds, arthritis, ulcers, constipation and even cholesterol counts.
Because placebos can produce so many desirable effects, no test of a new drug or other treatment is considered valid unless it compares the new agent with a placebo. The placebo is designed to look so much like the experimental treatment that neither the patient nor the doctor can tell which is which. This is called double-blind testing. The doctor knows only a code number for the treatment he dispenses. Only after the effects are recorded is the code broken to reveal who got the placebo and who got the real thing. Only if the experimental treatment’s effects are better than the placebo’s do scientists believe it is doing anything more than stimulating the placebo effect.
Endorphins cannot account for all placebo effects. There are scores of other special chemicals that nerve cells can put out, and researchers suspect they accomplish many placebo effects. Called neurotransmitters, they include serotonin, dopamine, norepinephrine and acetylcholine. These molecules can carry messages from one nerve cell to another (this is their classically understood role), and they can carry messages from the nervous system to almost any other cell of the body. Some even act on the cells of the immune system, boosting their capacity to fight infection.
Warts offer a dramatic example.
Warts are a benign tumor caused by a virus infection. They can sprout in clusters and persist for years, or they can go away for no obvious reason. They can also, as many doctors have known for centuries, go away through the placebo effect. For many years the famous Merck Manual, a thoroughly scientific compendium, advised doctors to “hex” warts with an impressive ritual such as painting the warts red and invoking mystical powers. It works best with children, the manual said.
In a controlled experiment reported in the British medical journal Lancet in 1959, volunteers with warts all over their bodies were hypnotized and told that the warts would disappear on one side but not the other. Within weeks, exactly that happened to most of the volunteers. Hypnosis is a legitimately amazing phenomenon in its own right, but its role in this case is thought to be that of a ritual that invokes the placebo power. “Abracadabra” would work as well, as long as the patient had good reason to believe it was truly a powerful word.
Doctors have been using the placebo force for thousands of years, whether they knew it or not. A good share of the benefit conferred by every therapeutic act, placebo research now reveals, comes from the placebo effect. Even if the drug or procedure has intrinsic benefits as well, the placebo effect will enhance the benefit--so long as patients have faith in their doctors.
Which raises the question of whether the modern trend toward demythologizing doctors and publicizing their fallibilities may be depriving their patients of genuinely beneficial placebo effects. If so, in a health care system based solely on reason, would one of the most powerful and versatile promoters of good health be lost?
